Method and apparatus of displaying three-dimensional arrival screen for navigation system

ABSTRACT

A method and apparatus of displaying a three-dimensional arrival screen allows the user to more easily and accurately identify the actual location of the destination by displaying the three-dimensional arrival screen which shows the relationship among the location of the destination, the locations of the neighboring addresses, and the current vehicle position. The method includes the steps of receiving a street address number of a destination, retrieving data indicating a road segment which includes the specified street address number, estimating positions of the destination and neighboring addresses based on street numbers of the destination, neighboring addresses, and position data of the road segment, and displaying a three-dimensional arrival screen when the user comes within the predetermined distance range from the destination.

FIELD OF THE INVENTION

This invention relates generally to a method and apparatus fordisplaying an image for a navigation system, and more particularly, to amethod and apparatus for displaying a destination arrival screen of athree-dimensional image for a navigation system that allows a user toeasily correlate an actual position of the destination with theaddresses, structures, and other indicators on the screen in theneighborhood of the destination, thereby more accurately detecting thearrival at the destination.

BACKGROUND OF THE INVENTION

A navigation system performs travel guidance for enabling a user toeasily and quickly reach the selected destination. A typical example isa vehicle navigation system where a vehicle is equipped with anavigation function to guide a driver to a destination through acalculated route. Such a navigation system detects the position of theuser's vehicle, and reads out map data pertaining to an area at thecurrent vehicle position from a data storage medium. Typically, thenavigation system displays a map image on a monitor screen whilesuperimposing thereon a mark representing the current vehicle position.At an intersection associated with the calculated route, the navigationsystem notifies the user which direction to turn at the intersection toreach the destination.

FIGS. 1A-1H show an example of overall procedure and screen displaysinvolved in the operation of the navigation system. FIG. 1A shows anexample of locator map screen of the navigation system when thedestination is not specified. Typically, the navigation system displaysa street on which the vehicle (vehicle position VP) is running on a mapimage and a name of the street. Other information such as a northpointer NP, a map scale and a current time may also be illustrated onthe display screen.

An example of process for specifying a destination in the navigationsystem through a Point of Interest (POI) search method is shown in FIGS.1B-1F. A main menu screen such as shown in FIG. 1B displays menu itemsincluding a “Destination” menu for entering the destination. Whenselecting “Destination”, the navigation system displays a “FindDestination by” screen as shown in FIG. 1C for specifying an inputmethod for selecting the destination. The “Find Destination By” screenlists various methods for selecting the destination including “Address”for specifying the city and address of the destination, “Intersection”for specifying the names of two streets which intersect with oneanother, and “Point of Interest (POI)” for selecting the programmeddestination based on the name, category or telephone number.

When selecting, the “Point of Interest” method in FIG. 1C, thenavigation system displays selection methods of point of interest (POI)either by “Place Name” or “Place Type” in FIG. 1D. The “Place Name” isto specify a name of POI, and the “Place Type” is to specify a categoryof POI. If the “Place Type” is selected in FIG. 1D, the navigationsystem lists categories of POIs as shown in FIG. 1E. The user selects adesired category of destination from the lists.

FIG. 1F shows a screen when the user has selected a “Fast Foods”category in the example of FIG. 1E. In this example, the screen includesthe name of POI type “Fast Foods” at the top and a list of names of thefast food restaurants typically sorted by distance from the currentposition. The user selects a particular restaurant among the restaurantlists for route guidance. In FIG. 1G, the navigation system determinesan appropriate route to the destination. After determining thecalculated route, the navigation system starts the route guidance asshown in FIG. 1H.

Typically, the navigation system will show an arrival screen such asshown in FIGS. 2A and 2B when the vehicle approaches the destination.The current vehicle position indicator 71 and the destination icon 91are shown on the map image. The screens shown in FIGS. 2A and 2B aresimilar to those displayed while the navigation system guides the userto the destination, except that the screens show the destination icon 91that indicates the location of the destination on the map image.

FIG. 2A shows the situation where the user is close to the destinationbut has not yet reached the destination while FIG. 2B shows thesituation where the vehicle has reached the destination. In FIG. 2B, thenavigation system announces that the vehicle has arrived at thedestination when the vehicle is within an arrival detection range suchas 200 yards. However, since the destination icon 91 on the map imagedoes not show the accurate location, when there are many houses orbuildings within the arrival detection range, the user has a problem oflocating the exact destination if it is a new place for the user. Thus,there is a need for a navigation system to allow the user to more easilyand accurately identify the actual location of the destination.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a methodand apparatus of displaying a three-dimensional arrival screen for anavigation system which shows more accurate relationship among thelocation of the destination, the locations of the neighboring addresses,and the current vehicle position.

It is another object of the present invention to provide a method andapparatus for displaying a three-dimensional arrival screen for anavigation system which shows position marks and street address numbersof the destination and neighboring addresses.

It is a further object of the present invention to provide a method andapparatus for displaying a three-dimensional arrival screen which isable to use building footprint data in combination with road segmentdata and address data for accurately defining the position of thedestination.

One aspect of the present invention is a method for displaying athree-dimensional arrival screen showing a positional relationship amongthe destination and neighboring addresses. The method includes the stepsof receiving a street address number of a destination specified by auser, retrieving data indicating a road segment which includes thespecified street address number thereon from a map information storage,estimating positions of the destination and neighboring addresses basedon street numbers of the destination, neighboring addresses, positiondata of the road segment, detecting whether the user comes within apredetermined distance range from the destination, and displaying athree-dimensional arrival screen when the user comes within thepredetermined distance range from the destination.

The three-dimensional arrival screen includes a position of thedestination, a current position of the user, a road on which the user ismoving, and street address numbers of the destination and theneighboring addresses. The three-dimensional arrival screen furtherincludes position marks showing the positions of the destination and theneighboring addresses. The three-dimensional arrival screen furtherincludes an image showing a topological shape of the building derivedfrom footprint data.

The method for displaying an arrival screen further includes the stepsof checking whether any footprint data exist adjacent to the roadsegment which includes the specified street address of the destination,and estimating positions of the destination and neighboring addresses byincorporating position information included in the footprint data. Thefootprint data of a building includes the position information which isexpressed by latitude and longitude data indicating a shape, size andlocation of the building, or other means.

The process of estimating the positions of the destination andneighboring addresses includes a process of interpolating between twostreet address numbers on the road segment when absolute positions ofthe two street address numbers are known. When footprint data isavailable, the process of estimating the positions by incorporating theposition information included in the footprint data includes a processof interpolating between a street address number on the road segment anda selected point on the road segment corresponding to the latitude andlongitude data of the building.

On the three-dimensional arrival screen, the position marks and streetaddress numbers are provided on one side of the road on which the useris moving where the destination is located on the one side.Alternatively, the position marks and street address numbers areprovided on both sides of the road on which the user is moving withoutregard to which side of the road the destination is located.

Another aspect of the present invention is an apparatus for displaying athree-dimensional arrival screen for a navigation system forimplementing the various steps of the method noted above. The navigationsystem is designed to determine accurate locations corresponding tostreet address numbers and displays more accurate relationship among thelocation of the destination, the locations of the neighboring addresses,and the current vehicle position on the three-dimensional arrivalscreen.

According to the present invention, the navigation system allows theuser to more easily and accurately identify the actual location of thedestination by displaying the three-dimensional arrival screen whichshows the relationship among the location of the destination, thelocations of the neighboring addresses, and the current vehicleposition. Since the three-dimensional arrival screen shows positionmarks and street address numbers of the destination and neighboringaddresses, the user is able to accurately specify the destination bycomparing the image on the three-dimensional screen with the outsideview.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1H are schematic diagrams showing an example of operationalprocess and screen displays involved in the navigation system forselecting a destination.

FIGS. 2A and 2B are schematic diagrams showing examples of screendisplay of a conventional navigation system, where FIG. 2A shows thesituation where the vehicle is close to the destination and FIG. 2Bshows the situation where the vehicle has reached the destination.

FIGS. 3A-3D are schematic diagram showing display examples of thenavigation under the present invention where FIGS. 3A and 3B show arelationship between two-dimensional and three-dimensional map imagesthat can be switched with one another, FIG. 3C shows the situation wherethe vehicle is close to the destination, and FIG. 3D shows the situationwhere the vehicle has arrived at the destination.

FIG. 4 is a schematic view showing the representation of roads,destination, road segments to describe the implementation of thethree-dimensional arrival screen method under the present invention.

FIGS. 5A and 5B are schematic diagrams showing display examples underthe present invention showing three-dimensional arrival screen whichinclude footprint data along the road in the neighborhood of thedestination.

FIGS. 6A and 6B are schematic views showing the representation of roads,destination, road segments to describe the implementation of the presentinvention which includes footprint data along the road in theneighborhood of the destination.

FIGS. 7A and 7B are schematic diagrams showing further examples ofthree-dimensional arrival screen under the present invention where FIG.7A is an arrival screen showing neighboring address locations on bothsides of the road, and FIG. 7B is an arrival screen showing crossroadsof the neighboring address locations.

FIG. 8 is a flow chart showing the operational steps of the presentinvention for estimating the location of the destination and neighboringaddresses along the road and displaying those locations and the streetaddress numbers on a three-dimensional arrival screen.

FIG. 9 is a block diagram showing an example of configuration of avehicle navigation system implementing the three-dimensional arrivalscreen of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will be described in detail with reference to theaccompanying drawings. In the present invention, the method andapparatus for a navigation system displays a destination arrival imagewhich is an intuitive three-dimensional view of a destination includingstreet address numbers in the neighborhood of the destination. When thevehicle approaches within a predetermined distance from the destination,the navigation system displays the three-dimensional arrival screenwhich includes a mark of the destination and its street address numberas well as neighboring street address numbers and position marks suchthat the user can readily correlate the present location and thelocations on the arrival screen.

Although the description is made for the case that the three-dimensionalarrival screen of the present invention is implemented to a vehicle, itshould be noted that the present invention can be implemented to otherdevices or transportation machine. For instance, the present inventionmay be implemented to a hand-held device having a navigation functionsuch as a PDA (personal digital assistant), a cellular phone, or alaptop computer.

FIGS. 3A-3D show display examples of the navigation system under thepresent invention where FIGS. 3A and 3B show a relationship betweentwo-dimensional and three-dimensional map images that can beautomatically or manually switched with one another. FIG. 3C shows thesituation where the vehicle is close to the destination, and FIG. 3Dshows the situation where the vehicle has arrived at the destination.When the user selects a destination through the procedure such as shownin FIGS. 1A-1H, the navigation system shows a map image to indicate acalculated route and a relative location of the vehicle on the mapimage.

As the vehicle approaches the destination and reaches within apredetermined distance from the destination, the navigation systemautomatically changes the two-dimensional map screen of FIG. 3A to athree-dimensional arrival screen of FIG. 3B. An example of thepredetermined distance is, for example, 100-200 yards that can beadjusted by the user. It is also possible that the user can manuallyswitches between the two-dimensional map screen of FIG. 3A and thethree-dimensional arrival screen of FIG. 3B through a switch-over key 76on the left side of the screens.

The three-dimensional arrival screen shown in FIGS. 3C and 3D give theuser an image similar to a three-dimensional outside view that the useractually sees in the neighborhood of the destination. Thethree-dimensional views of FIGS. 3C and 3D include a current positionindicator 71, the road on which the vehicle is running, a destinationindicator 91, and address indicators 93. The three-dimensional image maybe calculated and rendered on the display by using the map data in thenavigation system. As the vehicle comes closer to the destination, thenavigation system will change the display to reflect the currentposition of the user.

Thus, as the vehicle proceeds to the destination, the location of thedestination and neighboring spots on the display will changeaccordingly. The neighboring address indicators 93 include positionmarks and their street address numbers on the road that the user ismoving. The current position indicator 71 shows the current position ofthe vehicle that is moving on the road.

The position mark and street address number “19145” of the addressindicator 93 showing the destination are also associated with thedestination indicator 91 on the screen. The address indicators 93 alsoshow the position marks and street address numbers adjacent to thedestination. This facilitates the user to conceive the current vehicleposition relative to the destination and neighboring addressesaccurately.

FIG. 3D shows a destination arrival image which is a three-dimensionalview similar to that shown in FIG. 3C except that the vehicle hasreached the destination. Because the vehicle has further moved from thelocation shown in FIG. 3C, the address indicators 93 show additionalposition marks and street address numbers while some position marks andstreet address numbers in FIG. 3C are removed. The navigation system maygive a voice announcement indicating that the destination is reached.

FIG. 4 is a schematic view showing the relationship among thedestination, road segments and street address numbers to describe theimplementation of the display method under the present invention. Themap data storage in the navigation system stores the map informationincluding a large number of road segments. A road segment is a segmentthat represents one unit of a road, thus, one road may be subdividedinto a plurality of road segments. Each road segment has a start addressnumber and an end address number and an absolute location of its eachend is represented by latitude and longitude data (position data or nodedata).

Other than two ends of the road segment, the map data in the navigationsystem do not have information as to exact position of addresses locatedon the road segment. In other words, the map data include a streetaddress number and an absolute location of each end of the road segmentbut do not have the street address numbers and absolute locations on theintermediate of the road segment. The position data (start and end ofroad segment) indicate points at which road segments intersect with oneanother.

As noted above, in a navigation system, a road is configured byconnection of a plurality of road segments. Thus, in the example of FIG.4, a road “GRAMERCY” is configured by three road segments where an entrynode 72 is established at one end and an exit node 73 is established atanother end. In this example, it is assumed that the street addressnumber “19145” is the address of the destination which is indicated bythe destination indicator 91.

As noted above, the navigation system does not necessary haveinformation on all positions corresponding to all addresses along theroad. In the example of FIG. 4, only the locations for the addresses ateach end of a road segment are known with a high degree of preciseness.That is, the locations of the addresses for the street address numbers19300, 19200, 19140, and 19000 on the road “GRAMERCY” are known. Thelocations for addresses that are between the known street addressnumbers such as a street address number “19145” must be calculated todetermine an approximate (estimated) location thereof.

Thus, for displaying the street address numbers and position marks inFIGS. 3C and 3D, the navigation system interpolates the position of acertain street address number by dividing the road segment between thetwo ends of the road segment. For example, in FIG. 4, the location ofthe street address number “19145” is determined by dividing the roadsegment that starts with the street address number “19140” and ends withthe street address number “19200” in proportion to the numerical valueof the street address number “19145”. Thus, in the three-dimensionalviews of FIGS. 3C and 3D, the navigation system displays the location ofthe destination along with the locations of the neighboring streetnumbers.

FIGS. 5A and 5B show three-dimensional arrival screens of the presentinvention where FIG. 5A shows the situation where the vehicle is closeto the destination and FIG. 5B shows the situation where the vehicle hasarrived at the destination. In the example of FIGS. 5A and 5B, thenavigation system displays the three-dimensional arrival screen whichincludes the destination associated with building footprint data.Namely, the three-dimensional arrival screen also shows an image ofbuilding footprint in addition to the example of FIGS. 3C and 3D.

Generally, the recent map data include footprint data (also referred toas “polygon data”) showing a topological shape of a relatively largestructure. The footprint data define the topological shape of such alarge structure by absolute positions of corner points of the structureby latitude and longitude values. Since the building footprint datainclude accurate position information, it is expected that the buildingfootprint data help in estimating an accurate location of a destinationby incorporating the position information.

Therefore, the three-dimensional views of FIGS. 5A and 5B show a currentvehicle position indicator 71, the road on which the user's vehicle isrunning, a destination indicator 91, a topological shape 95 based on thebuilding footprint data, and neighboring address indicators 93. In thisexample, the destination is represented by the building footprint, whichwill be described later in detail with reference to FIG. 6, in additionto the destination indicator and the street address number. As thevehicle comes closer to the destination, the navigation system willchange the display to reflect the change of the vehicle position on thethree-dimensional screens.

Since the footprint data include information on the absolute locationsof the structure, if the destination is associated with such astructure, the navigation system can estimate the location of thedestination more accurately. The location of the destination thusestimated is displayed on the three-dimensional screen in combinationwith the street address numbers of neighboring addresses, thus, the usercan determine the actual location of the destination. Although thefootprint area is a simple rectangular shape in this example, it cantake any other shape to conform to the shape of the actual structure ornatural object.

FIGS. 6A and 6B are schematic views showing the relationship among thedestination, road segments, building footprint, and address streetnumbers to describe the implementation of the display method under thepresent invention in the situation corresponding to FIGS. 5A and 5B. Inthe example of FIG. 6A, a topological shape of the building 95 at thedestination “19145 GRAMERCY” is illustrated based on the footprint data.In the footprint data, at least each corner point of the buildingfootprint is given by an absolute position expressed by latitude andlongitude values. Thus, such corner positions can be used to correlatewith the positions of the end of the road segment on which thedestination is located to accurately assign the locations on the roadsegment.

Thus, in the example shown in FIGS. 6A and 6B, not only the locationsfor the addresses at the ends of road segments, but also the topologicalshape of the building 95 is included to correlate with the locations onthe road segments. That is, the locations of the addresses for thestreet address numbers 19300, 19200, 19140, 19000 as well as thelocation of the footprint having the address of 19145 are known. Sincethe destination is also expressed by the building footprint, the usercan easily determine the actual arrival of the destination by comparingthe three-dimensional screen of the navigation system and an actual viewoutside of the vehicle.

FIG. 6B shows another situation where there exist building footprintdata adjacent to the address of the destination. In this example, themap data include footprint data of a building 99 on the road(destination) segment with the street address number “19160”. Becausethe street address number of the building 99 is “19160”, the navigationsystem determines that the position on the road segment corresponding tothe lower end (marked by point P) of the building 99 has the addressnumber “19160”. Thus, the locations of the street address number “19145”of the destination and neighboring addresses are determined byinterpolating between the absolute positions of the address numbers“19160” and “19140”. As a result, the locations of the destination andthe neighboring addresses can be displayed on the three-dimensionalarrival screen of FIGS. 5A-5B with high accuracy.

FIGS. 7A and 7B show other examples of three-dimensional arrival screenthat include the destination and neighboring areas. In FIG. 7A, thethree-dimensional arrival screen includes street address numbers on bothsides of the road. Namely, address indicators 93 showing position marksand street address numbers are provided on the three-dimensional screennot only on the side where the destination is located but also on theother side as well. The user can easily identify the present location bycomparing the actual view with the addresses on both sides of the road.

Although the three-dimensional arrival screen shown and described aboveillustrate a straight road along which the destination and neighboringaddresses are located, the arrival screen may also show a curved road oran intersection depending on the location where the destination islocated. FIG. 7B shows such an example where the three-dimensionalarrival screen shows an intersection in the case where a destination islocated close to the intersection. Since an image of the intersection isalso included in the three-dimensional arrival screen, the user caneasily correlate the map image on the arrival screen with the actualroad situation.

Further, the images on the three-dimensional arrival screen in thenavigation system may vary to reflect the actual street condition. Incase where there is a well-known scenic area in the neighborhood of thedestination, the navigation system may show such a symbol on thedisplay. Moreover, icons of well-known franchise restaurants may be alsoshown on the three-dimensional arrival screen so that the user is ableto identify the current location comparing with the well-knownrestaurant relative to the destination.

An example of operational steps for conducting the present invention isdescribed with reference to the flow chart of FIG. 8. As describedabove, the present invention estimates the location of the destinationand neighboring addresses along the road and displays the street addressnumbers of those locations on a three dimensional screen. As the userselects a destination and the navigation system determines the route tothe destination as described with reference to FIGS. 1A to 1H, thenavigation system starts the operation of estimating the location of thedestination and neighboring addresses.

In step 101, the navigation system determines the street address (house)number of the destination. In the case described with reference to FIGS.3C-3D and 4, the street address number of the destination is “19145”.The navigation system then determines a range of street address numberof the road segment (destination segment) that should have the streetaddress number “19145” in step 102. In the example of FIGS. 3C-3D and 4,the road segment having the street address number range between “19140”and “19200” on the road “GRAMERCY” is the destination segment.

In step 103, the navigation system determines the street address numberrange from the entry node and the exit node of the road “GRAMERCY”. Inthe above example, the street address number ranges from “19000” at theentry node to “19300” at the exit node as shown in FIG. 4. Next, at step104, the navigation system checks the map data file 111 whetherfootprint data exists between the entry and exist node of the road“GRAMERCY”.

As noted above with reference to FIGS. 5A-5B and 6, the recent map datainclude footprint data (polygon data) of relatively large structures ornatural objects that express topological shape thereof. Thus, when thedestination is specified, the navigation system checks the map data file111 as to whether there is any polygon (footprint) data associated withthe street segment. Namely, the navigation system checks whether thereis any structure accompanied by footprint data defined by latitude andlongitude data.

If no footprint data exists between the entry node and exist node, atstep 105, the navigation system calculates the locations of thedestination and neighboring addresses by interpolating the streetaddress numbers on the road segment between the two ends. In the exampleof FIGS. 3C-3D and 4, the street address number “19145” is located onthe road (destination) segment between the address range from “19140” to“19200”. Thus, the navigation system proportionally divides thelocations on the road segment between the street address numbers “19140”to “19200” by the difference which, in this case, is “60”. Then, thelocation corresponding to the difference “5” between the street addressnumber “19140” and the street address number “19145” is allocated on theroad segment.

Then, in step 106, the navigation system displays the three-dimensionalarrival screen showing the destination and the neighboring addresseswith street address numbers. As shown in FIG. 3C, the address indicators93 show position marks and street address numbers of the destination andneighboring addresses on the three-dimensional arrival screen which alsoinclude the indicators showing the current vehicle position anddestination. When the vehicle comes sufficiently close to thedestination on the three-dimensional arrival screen as shown in FIG. 3D,the navigation system announces the arrival at the destination at step107.

In the above noted step 104, if it is determined that the buildingfootprint data exists between the exit node and the entry node, theprocess moves to a step 108 where the navigation system calculates moreaccurate positions of the street address numbers on the road segment.This procedure is done by combining the absolute locations of the pointson the building footprint with the absolute locations of the ends of theroad segment and interpolating between the two adjacent absolutelocations. Thus, the navigation system is able to accurately determinethe locations of the street address numbers of the destination andneighboring addresses.

After the calculation, the navigation system displays the destinationand neighboring address spots on the three-dimensional arrival screen asshown in FIG. 5A when the vehicle comes close to the destination in step109. As shown in FIG. 5A, the address indicators 93 show position marksand street address numbers of the destination and neighboring addresseson the three-dimensional arrival screen and the building footprintimage. The three-dimensional arrival screen also includes the indicatorsshowing the current vehicle position and destination. When the vehiclecomes sufficiently close to the destination on the three-dimensionalarrival screen as shown in FIG. 5B, the navigation system announces thearrival at the destination.

FIG. 9 shows an example of structure of a vehicle navigation system forimplementing the present invention. While the vehicle navigation systemis explained for an illustration purpose, the present invention can alsobe applied to other types of navigation system, such as a portablenavigation device implemented by a PDA (personal digital assistant)device, other hand-held devices such as a wireless telephone, or alaptop or notebook computer.

In the block diagram, the navigation system includes a data storagemedium 31 such as a hard disc, CD-ROM, DVD or other storage means(hereafter “data disc”) for storing the map data. The navigation systemincludes a control unit 32 for controlling an operation for reading theinformation from the data storage medium 31, and a position measuringdevice 33 for measuring the present vehicle position or user position.For example, the position measuring device 33 has a vehicle speed sensorfor detecting a moving distance, a gyroscope for detecting a movingdirection, a microprocessor for calculating a position, a GPS (globalpositioning system) receiver, and etc.

The block diagram of FIG. 9 further includes a map information memory 34for storing the map information which is read from the Data disc 31, adatabase memory 35 for storing database information such as point ofinterest (POI) information which is read out from the data storagemedium 31, a remote controller 37 for executing a menu selectionoperation, an enlarge/reduce operation, a destination input operation,etc. and a remote controller interface 38. Although a remote controlleris a typical example for selecting menus, executing selected functionsand etc., the navigation system includes various other input methods toachieve the same and similar operations done through the remotecontroller.

In FIG. 9, the navigation system further includes a bus 36 forinterfacing the above units in the system, a processor (CPU) 39 forcontrolling an overall operation of the navigation system, a ROM 40 forstoring various control programs such as a route search program and amap matching program necessary for navigation control, a RAM 41 forstoring a processing result such as a guide route, a display controller43 for generating map image (a map guide image or an arrow guide image)on the basis of the map information, a VRAM 44 for storing imagesgenerated by the display controller 43, a menu/list generating unit 45for generating menu image/various list images, a synthesizing unit 46, athree-dimensional arrival screen controller 47, a wireless transmitter49 for wireless communication to retrieve data from a remote server, abuffer memory 48 for temporally storing data for ease of dataprocessing, and a monitor (display) 50.

The three-dimensional arrival screen controller 47 controls theoperation to display the three-directional arrival screen such as shownin FIG. 3C-3D, 5A-5B, and 7A-7B. The three-dimensional arrival screencontroller 47 can be a CPU 39 noted above or a separate processor. Thethree-dimensional arrival screen controller 47 performs a function ofthe present invention for establishing the relationship among the streetaddress numbers on the road segment and the actual positions of thedestination and neighboring addresses and displaying the relationshipwith on three-dimensional arrival screen.

The three-dimensional arrival screen controller 47 reads out map datafrom the map information memory 34 to compute the position of thedestination. By learning the actual locations of the destination and theneighboring addresses, the navigation system records the updated addressdata in the buffer memory 49. Thus, the navigation method and system isable to more accurately determine the positions of the destination andneighboring addresses so that it can accurately display the positionalrelationship on the three-dimensional arrival screen.

As has been described above, according to the present invention, thenavigation system allows the user to more easily and accurately identifythe actual location of the destination by displaying thethree-dimensional arrival screen which shows the relationship among thelocation of the destination, the locations of the neighboring addresses,and the current vehicle position. Since the three-dimensional arrivalscreen shows position marks and street address numbers of thedestination and neighboring addresses, the user is able to accuratelyspecify the destination by comparing the image on the three-dimensionalscreen with the outside view.

Although the invention is described herein with reference to thepreferred embodiment, one skilled in the art will readily appreciatethat various modifications and variations may be made without departingfrom the spirit and scope of the present invention. Such modificationsand variations are considered to be within the purview and scope of theappended claims and their equivalents.

1. A method for displaying an arrival screen for a navigation system,comprising the following steps of: receiving a street address number ofa destination specified by a user; retrieving data indicating a roadsegment which includes the specified street address number thereon froma map information storage; estimating positions of the destination andneighboring addresses based on street numbers of the destination,neighboring addresses, and position data of the road segment; detectingwhether the user comes within a predetermined distance range from thedestination; and displaying a three-dimensional arrival screen when theuser comes within the predetermined distance range from the destination;wherein the three-dimensional arrival screen includes a position of thedestination, a current position of the user, a road on which the user ismoving, and street address numbers of the destination and theneighboring addresses.
 2. A method for displaying an arrival screen asdefined in claim 1, wherein said step of estimating the positions of thedestination and neighboring addresses includes a step of interpolatingbetween two street address numbers on the road segment when absolutepositions of the two street address numbers are known.
 3. A method fordisplaying an arrival screen as defined in claim 1, wherein saidthree-dimensional arrival screen further includes position marks showingthe positions of the destination and the neighboring addresses.
 4. Amethod for displaying an arrival screen as defined in claim 1, furthercomprising the steps of: checking whether any footprint data existadjacent to the road segment which includes the specified street addressof the destination; and estimating positions of the destination andneighboring addresses by incorporating position information included inthe footprint data; wherein the footprint data of a building includesthe position information which is expressed by latitude and longitudedata indicating a shape, size and location of the building.
 5. A methodfor displaying an arrival screen as defined in claim 4, wherein saidstep of estimating the positions by incorporating the positioninformation included in the footprint data includes a step ofinterpolating between a street address number on the road segment and aselected point on the road segment corresponding to the latitude andlongitude data of the building.
 6. A method for displaying an arrivalscreen as defined in claim 4, wherein said three-dimensional arrivalscreen further includes an image showing a topological shape of thebuilding derived from the footprint data.
 7. A method for displaying anarrival screen as defined in claim 3, wherein said position marks andstreet address numbers are provided on one side of the road on which theuser is moving where the destination is located on said one side.
 8. Amethod for displaying an arrival screen as defined in claim 3, whereinsaid position marks and street address numbers are provided on bothsides of the road on which the user is moving without regard to whichside of the road the destination is located.
 9. A method for displayingan arrival screen as defined in claim 1, further comprising the step ofswitching between a two dimensional screen and the three-dimensionalscreen at any desired time by operating a switch-over key.
 10. A methodfor displaying an arrival screen as defined in claim 3, wherein saidthree-dimensional arrival screen further includes an image of anintersection when the intersection is located close to the destination.11. An apparatus for displaying an arrival screen for a navigationsystem, comprising: means for receiving a street address number of adestination specified by a user; means for retrieving data indicating aroad segment which includes the specified street address number thereonfrom a map information storage; means for estimating positions of thedestination and neighboring addresses based on street numbers of thedestination, neighboring addresses, and position data of the roadsegment; and means for detecting whether the user comes within apredetermined distance range from the destination; means for displayinga three-dimensional arrival screen when the user comes within thepredetermined distance range from the destination; wherein thethree-dimensional arrival screen includes a position of the destination,a current position of the user, a road on which the user is moving, andstreet address numbers of the destination and the neighboring addresses.12. An apparatus for displaying an arrival screen as defined in claim11, wherein said means for estimating the positions of the destinationand neighboring addresses includes means for interpolating between twostreet address numbers on the road segment when absolute positions ofthe two street address numbers are known.
 13. An apparatus fordisplaying an arrival screen as defined in claim 11, wherein saidthree-dimensional arrival screen further includes position marks showingthe positions of the destination and the neighboring addresses.
 14. Anapparatus for displaying an arrival screen as defined in claim 11,further comprising: means for checking whether any footprint data existadjacent to the road segment which includes the specified street addressof the destination; and means for estimating positions of thedestination and neighboring addresses by incorporating positioninformation included in the footprint data; wherein the footprint dataof a building includes the position information which is expressed bylatitude and longitude data indicating a shape, size and location of thebuilding.
 15. An apparatus for displaying an arrival screen as definedin claim 14, wherein said means for estimating the positions byincorporating the position information included in the footprint dataincludes means for interpolating between a street address number on theroad segment and a selected point on the road segment corresponding tothe latitude and longitude data of the building.
 16. An apparatus fordisplaying an arrival screen as defined in claim 14, wherein saidthree-dimensional arrival screen further includes an image showing atopological shape of the building derived from the footprint data. 17.An apparatus for displaying an arrival screen as defined in claim 13,wherein said position marks and street address numbers are provided onone side of the road on which the user is moving where the destinationis located on said one side.
 18. An apparatus for displaying an arrivalscreen as defined in claim 13, wherein said position marks and streetaddress numbers are provided on both sides of the road on which the useris moving without regard to which side of the road the destination islocated.
 19. An apparatus for displaying an arrival screen as defined inclaim 11, further comprising means for switching between a twodimensional screen and the three-dimensional screen at any desired timeby operating a switch-over key.
 20. An apparatus for displaying anarrival screen as defined in claim 13, wherein said three-dimensionalarrival screen further includes an image of an intersection when theintersection is located close to the destination.